Conventionally, bolts are used to fixedly connect two objects by extending through the two objects and engaging it with a nut. In some situations, the bolts are not supposed to be disengaged easily, such as the bolts used to connect license plates to a car or to assemble casings in which products are displayed to public. In order to achieve an antitheft feature, some specially designed bolts and methods to employ the bolts have been developed. In one such case, the head portion of the special designed bolt is removed from the shank after the bolt extends through the objects. This requires special tool and is used in special situations. In normal situations and in order to conveniently use the bolts, the bolts and the nut are easily accessed so that they can also be disengaged from the objects by using a simple tool such as a wrench.
The present invention intends to provide an antitheft device which has a base member and a cap mountable to the base member so as to enclose the head portion and/or the nut therein. The present antitheft invention has arisen to mitigate and/or obviate the disadvantages of the conventional antitheft device.